July 24, 2009 -- Sniffing your way around the local farmer's market may offer some of nature's best aromatherapy to reduce stress.

A new study shows that linalool, a floral scented compound found in many foods and flowers such as oranges, grapes, mangos, lemons, basil, and lavender, may suppress stress-related chemical and gene changes in rats.

Inhaling the linalool caused a reduction in the level of stress-induced immune cells in the rats' bloodstream as well as downgraded the activity of more than 100 genes that go into overdrive during stressful situations.

Researchers say inhaling the scents of certain plants has been practiced since ancient times to reduce stress, fight inflammation and depression, and induce sleep, and these results represent some of the first scientific evidence to back up these stress-reducing claims.

Good Reason to Stop and Smell the Flowers

In the study, published in the Journal of Agricultural and Food Chemistry, Japanese researchers exposed a group of laboratory rats to the scent of linalool during a stressful situation and then monitored changes in their blood chemistry and gene activity. The test group was compared to rats who were stressed the same way but without linalool exposure and rats who were neither stressed nor exposed to linalool.

Although levels of two stress hormones, ACTH and corticosterone, increased in the stressed rats exposed to linalool scent, the results showed that linalool exposure was linked to a return of two types of stress-related immune cells to near-normal levels compared to the stressed rats who were not exposed to linalool.

In addition, inhaling linalool was linked to reduced activity of 109 genes that kick into high gear in response to stress.

Researcher Akio Nakamura of the Technical Researcher Center at T. Hasegawa Co. Ltd. in Kawasaki-shi, Japan, and colleagues say the findings could form the basis for additional study using blood tests to identify effects of odorants.